Continuous boiler blowdown apparatus



Jan. 13, 1942. P. E. MADDEN A 2,270,067

CONTINUOUS BOILER BLOWIOWN APPARATUS 2 Sheets-Sheet 1 Filed May 23, 1938Jan. 13, 1942. A|= E. MADDl-:N 2,270,067

CONTINUOUS BOILER BLOWDOWN APPARATUS Filed May 23, 19:58 2 sheets-smet 2s; A y

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` f' I v Para? Jaa/a/efe Patented `lian. 13, 1942 coN'rlNuoUs BoILERBLoWDoWN APPARATUS Paul E. Madden, Chicago, Ill.

Application May 23, 1938, Serial No. 209,568

8 Claims.

My invention relates to improvements in boiler treatment apparatus andhas for one object to provide an apparatus which is applicable tocontinuous boiler blow down. Another object is to provide a new andimproved form of apparatus for boiler sludge deconcentration. Anotherobject of my invention is to provide means for protecting the continuousblow down nozzle or orice against clogging. Other objects will appearfrom time to time throughout the specification and claims.

My invention is illustrated more or less diagrammatically in theaccompanying drawings, wherein- Figure 1 is a side elevation of a boilershowing my apparatus in position;

Figure 2 is a detail section through the heat interchange and sludgedeconcentration portion of the apparatus;

Figure 3 is a detail section through a modified form of the apparatuswhere the sludge deconcentrator has been omitted;

Figure 4 is a detail section through a further modification omittingheat interchange.

Like parts are indicated by like characters throughout the specicationand drawings.

It is understood that the purpose of a continuous blow-down from a steamboiler and the like is to maintain the concentration of salts and otherdeposits in the liquid in the boiler at a substantially constant point.All that is necessary in order to do this is to provide for means whichwill continuously vbleed off or blow down from the boiler a controlledquantity of water. Preferably this water is drawn from the boiler at thepoint where the solids concentration is a maximum. So far as myinvention is concerned, it makes no difference how this is done or whatkind of a collector or where the pipe is connected to the boiler. Suiceit to say, there must be a continuous connection with the liquidcontents of the boiler such that a continuous quantity of the liquid isblown down. The actual amount discharged depends, of course, upon thesize of the boiler, the character of the water fed to it and the rate atwhich steam is evaporated and it is desirable to provide means which canbe easily set or adjusted by the operator to change or control the rateof flow. It is highly important that when this is done the setting beaccurate and definitely known to the operator as even a slight deviationfrom the correct blown down rate will result in greatly decreasedefficiency in boiler operation.

I propose also to associate with the continuous blowdown, sludgedeconcentration means whereby the water in the boiler in much largerquantity than that blown down will circulate through a sludgedeconcentration chamber, the sludge being deposited or settled out inthat chamber, the water with a smaller amount of sludge being returnedto the boiler.

The continuous blow down takes out of the boiler system not merelyprecipitated solids but solids in solution. The sludge deconcentratortakes care only of precipitated solids. Under some circumstances, it issufcient to use the continuous blow-down alone. Under manycircumstances, it is desirable to useboth the continuous blow-down andsludge deconcentrator and I propose to combine the two so as to haveeach assist in the operation of the other.

In connection with continuous blow down, if the blow-down water isdischargedwithout further treatment, the heat of that water is lost and'wasted. Therefore, it is frequently desirable to use a heat interchangearrangement whereby the blow-down water will transfer some of its heatto the boiler feed water, which water is subsequently returned to theboiler, thus decreasing heat loss. Y f

Moreover, in order to promote circulation of the water through thesludge deconcentrator, it is desirable also to provide means for coolingwater after it has left the boiler and before it reaches the sludgedeconcentrator as otherwise satisfactory circulation through the sludgedeconcentrator cannot be relied upon.

By combining the sludge deconcentrator 'and continuous blow-down withthe heat interchange desirable for both and by further using thecontinuous blow-down to assist circulationthrough the sludge interchangezone, Iobtain a materially improved result. i

I is the upper, 2 is the lower drumjand'3 are the circulating watertubes joining the twodrums of a boiler. The water level is as'indicated. y1?,1i`s a blowdown pipe, the intake end of which liesbeneath the level of the water in the boiler. The discharge end isconnected to a heat interchange header 5, closing one columnr 6, of aheat interchanger. This heat interchanger has another parallel column 'lprovided with a header 8, to which is connecteda discharge pipe 9,leading,to an adjustable metering continuous blowfdown valve I0.Associated with the headers 5 and 8, are water tubes Il, through whichthe boiler blow-down water may circulate. Boiler `feed water entersthrough a pipe I2, into the upper end ofthe heat interchange column' 1,passes down around the pipes I I, across through a connecting pipe I3 tothe lower end of the column 6 up around the pipes I I and out through apipe I4 to discharge into the feed water heater 35 showndiagrammatically.

The lower ends of the columns S and 'I communicate with passages I5 andIB respectively, which passages each communicate with the top of a drumor sludge deconcentrator I'I, which sludge deconcentrator is providedwith a discharge passage I8 at the bottom, controlled by a valve I9.Immediately below the column 1, and at the upper end of the passage I6,is a screen 20, the orices of which are small enough so that anyparticle which passes through the screen may pass through the meteringnozzles in the valve I0 without clogging.

2I, is a pipe leading from the passage I6 to communicate with the pipeI4, so that water may circulate from the pipe I4, through the column i5,passage I5, into the sludge deconcentrator I'I, thence out through thepassage I6, and pipe 2l, to the boiler. Because the boiler feed water iscolder than the water withdrawn from the body of the boiler, thetemperature in the pipes II, will be reduced, thus tending to promotedownward ow of water through the sludge deconcentration system.

A portion of the water which leaves the boiler 4, instead of returningto the boiler through the pipe 2l, passes up through the column 'I,being further cooled by contact with the feed water and is dischargedthrough the pipe 9, to the continuous blow down valve Il), and thencethrough the pipe 22, for discharge from the boiler syst-em.

23 is a sampling cock whereby the water from the continuous blow downmay be sampled.

With this arrangement the desired flow of water from the boiler throughthe column 5, is

promoted in the change in temperature resulting from the heatinterchange. It is further encouraged by the fact that there is acontinuous withdrawal from the system of water from the pipe 9 so thatthese two factors both tend to promote flow, or thermostaticcirculation, of water to and through the sludge deconcentrator.

If it is desired for any reason to eliminate the sludge deconcentrationidea from the system altogether, there is substituted for the passages iI5 and I6, a single chamber 24 having two upper branches 25 and 26, 25being equipped with a screen 20, as was passage I5 in Figure 2. The blowdown water comes downwardly through the pipes II, is discharged into thechamber 24,y

through the passage 25. Its direction is reversed. Its Velocity isdecreased by the increase in size of the chamber, solid matter issettled out in the chamber 24 and water free from large particles whichmight tend to clog the metering valve passes up through the screen 20,and tubes II, to the continuous blow-down as shown in Figure 3.

If, in addition it is desired to omit the complication of the heatinterchange, then a header 21, is substituted for the header 5, on thepipe 4. This header has a pipe 28, extending downwardly inside thechamber 29, associated with the header. The screen 30, is at the top ofthe pipe.A The chamber 23, the discharge valve Ill associated with itslower end, and the pipe 9, is connected to the header above the screen30, so that the water from the boiler passes down into the chamberthrough the pipe 2B, is reduced in velocity, its direction is reversed,large particles of scale or other sediment are settled in the chamber 29and the water free from sediment passes through screen 30 to blow-downpipe 9 thence through the metering valve which controls the rate offlow.

The metering valve controlling the continuous blow-down here illustratedis identical with the valve illustrated in my co-pending applicationcovering a metering valve though obviously any desirable type ofmetering valve might be used interchangeably with it in the system hereillustrated.

I claim:

1. In a continuous blow-down system for boilers and the like, twogenerally parallel vertical housings connected at their lower ends,means for feeding cooling water to one and withdrawing it from the otherat their upper ends, hot water pipes extending through both saidhousings, a supply pipe connected to the hot water pipes at the top ofone of said housings, a metering valve and a connection between it andthe hot water pipes in the other housing, a connection between the hotwater pipes in both housings including a settling chamber.

2. In a continuous blow-down system for boilers and the like, twogenerally parallel vertical housings connected at their lower ends,means for feeding cooling water to one and withdrawing it from the otherat their upper ends, hot water pipes extending through both saidhousings, a supply pipe connected to the hot water pipes at the top ofone of said housings, a metering valve and a connection between it andthe hot water pipes in the other housing, a connection between the hotwater pipes in both housings including a settling chamber and aconnection between the Vboiler and the hot water system above the top ofthe settling chamber.

3. A water treating apparatus adapted to be associated with a boiler,comprising a pair of parallel vertically disposed hollow columns,separate headers closing the upper ends of each, a single header havinga U-shaped chamber closing and joining the lower ends of the columns,apertured partitions in top and bottom of each column, a pipe connectedto the header at the top of one column, pipes located in the columnsregistering with the apertures in the partitions, a discharge pipeleading from the other upper header, a metering valve therein, a boilersupply pipe communicating with the upper end of one of said columns, apassage joining the lower ends of the columns, and a boiler supply pipeleading from the upper end of the second column, the passage and pipesbeing located between the apertured partitions.

4. A water treating apparatus adapted to be associated with a boilercomprising a pair of parallel vertically disposed hollow columns,separate headers closing the upper ends of each, a single header havinga U-shaped chamber closing and joining the lower ends of the columns,apertured partitions in top and bottom of each column, a pipe connectedto the header at the top of one column, pipes located in the columnsregistering with the apertures in the partitions, a discharge pipeleading from the other upper header, a metering valve therein, a boilersupply pipe communicating with the upper end of one of said columns, apassage joining the lower ends of the columns, and a boiler supply pipeleading from the upper end of the second column, the

; passage and pipes being located between the apertured partitions, thedischarge pipes and the boiler supply pipes being so related that theliquid in the two systems associated with said pipes flows in oppositedirections.

5. A water treating apparatus adapted to be associated with a boiler,comprising a pair of parallel vertically disposed hollow columns,separate headers closing the upper ends of each, a single header havinga settling chamber closing and joining the lower ends of the columns,apertured partitions in top and bottom of each column, a pipe connectedto the header at the top of one column, pipes located in the columnsregistering with the apertures in the partitions, a discharge pipeleading from the other upper header, a metering valve therein, a boilersupply pipe communicating with the upper end of one of said columns, apassage joining the lower ends of the columns, and boiler supply pipeleading from the upper end of the second column, the passage and pipesbeing located between the apertured partitions, a sludge pipecommunicating with the settling chamber at its lower extremity and avalve controlling said pipe.

6. A water treating apparatus adapted to be associated with a boiler,comprising a pair of parallel vertically disposed hollow columns,separate headers closing the upper ends of each, a single header closingthe lower ends of the columns, apertured partitions in top and bottom ofeach column, a pipe connected to the header at the top of one column,pipes located in the columns registering with the apertures in thepartitions, a discharge pipe leading from the upper header, a meteringvalve therein, a boiler supply pipe communicating with the upper end ofone of said columns, a passage joining the lower ends of the columns anda boiler supply pipe leading from the second column, the passage andpipes being located between the apertured partitions, an elongatedvertically disposed settling chamber supported by the single header,there being a passage in the header between each column and the settlingtank, a water return pipe communicating with one of the passages in thesingle header and leading thence to the boiler at a point below thepoint from which the boiler discharge pipe leads.

7. A water treating apparatus adapted to be associated with a boiler,comprising a pair of parallel vertically disposed hollow columns,separate headers closing the upper ends of each, a single header closingthe lower ends of the columns, apertured partitions in top and bottom ofeach column, a pipe connected to the header at the top of one column,pipes located in the columns registering with the apertures in thepartitions, a discharge pipe leading from the other upper header, ametering valve therein, a boiler supply pipe communicating with theupper end of one of said columns, a passage joining the lower ends ofthe columns and a boiler supply pipe leading from the second column, thepassage and pipes being located between the apertured partitions, anelongated vertically disposed settling chamber supported by the singleheader, there being a passage in the header between each column and thesettling tank, a water return pipe communieating with one of thepassages in the single header and leading thence to the boiler at apoint below the point from which the boiler discharge pipe leads, thepipes being so disposed that the water discharged from the boiler passesdownwardly through one column into the top of the settling tank, thenceupwardly through the other column to the discharge, the pipe returningto the boiler being connected with the passage leading to the headerfrom which the boiler water is discharged, the pipes associated with thefeed water system being adapted to cause circulation through the columnsin the opposite direction.

8. A continuous blow down system for boilers and the like including aheat interchange housing having hot and cold water compartments, aninlet and an outlet for the cold water compartment, means for supplyingboiler water to the hot water compartment, and a settling chamber below,directly connected to, and adapted to receive boiler water and sedimentdirectly from the hot water compartment, all of the walls of the hotwater compartment and the settling chamber except the iloor of thelatter, being so disposed as to guide settled sediment directly from thehot water compartment, under the force of gravity independent of theflow of the boiler water to the floor of the settling chamber, a passageleading upwardly from the upper portion of the settling chamber for thedischarge of the boiler water, a metering valve in the passage for thedischarge of the boiler water controlling the flow of watertherethrough, means for returning to the boiler part of the wateroriginally supplied to the heat interchange housing after it has beencooled and sedimentation has been settled out from it.

PAUL E. MADDEN.

